1. Field of the Invention
This invention relates to a resin sealing-type semiconductor device wherein a semiconductor chip with a large amount of heat generation formed by bipolar transistors and an LSI chip with a small amount of heat generation such as a microcomputer formed by MOS transistors are resin-molded in an identical package and a method for manufacturing the same.
2. Description of the Related Art
In a semiconductor device used in a TV receiver, a semiconductor chip forming a power amplifying circuit to amplify a received signal and an LSI chip forming a microcomputer for various types of control of this electrical power amplifying circuit are integrally molded by an identical resin.
In addition, in a motor, an electric power semiconductor chip to supply an electric current to a coil and a controlling semiconductor chip formed by MOSFETs, to control the electric power semiconductor chip are integrally molded by an identical resin. A complex resin sealing-type semiconductor device wherein an electric power semiconductor chip and a controlling semiconductor chip are integrally resin-molded as such has been used in many cases.
FIG. 7 and FIG. 8 are a sectional view and a plan view of a related-art complex resin sealing-type semiconductor device. A semiconductor chip 1 to form a power amplifying circuit, etc., is composed of bipolar-type transistors. These semiconductor chips 1 are bonded to die pad portions 2A of a lead frame 2, and external electrode lead-out bonding pads 3 of the semiconductor chip 1 are wire-bonded to outer leads 5 of the lead frame 2 via thin metal wires 6.
Similarly, an LSI chip 7 to form a microcomputer is formed of MOSFETs. These LSI chips 7 are bonded to die pad portions 2B of the lead frame 2, and external electrode lead-out bonding pads 9 of the LSI chip 7 are wire-bonded to outer leads 5 of the lead frame 2 via thin metal wires 10.
The semiconductor chip 1 and IC chip 7 attached to the lead frame 2 are placed in a molding die except for the outer leads 5 which are respectively wire-bonded, and are transfer-molded by injecting a molding resin 11 into the molding die.
In a related-art resin sealing-type semiconductor device, an integrated circuit chip composed of bipolar-type transistors forming a power amplifying circuit to amplify a signal and an integrated circuit chip composed of MOS-type transistors have been integrally molded by an identical resin.
Herein, since a semiconductor chip forming a power amplifying circuit has a large amount of heat generation, it is necessary to release the generated heat by transmitting the same by use of a resin with an excellent thermal conductivity. However, this is costly since a high thermal conductive resin is more expensive than a non-high thermal conductive resin generally used for resin sealing.
In addition, alumina is blended in a resin to obtain a high thermal conductive resin. In this case, since the high thermal conductive resin becomes great in stress compared to a generally used low-stress resin, this causes a distortion in a semiconductor chip to be molded.